@matheusbsbs / matheus-bagliano / commits / c333c2ce65

test-mergesort: use mem_pool for sort input

The previous patch almost halved the number of heap allocations for the sort subcommand. Reduce it further by using a mem_pool for the line objects. Note that t/perf/run can't be used directly to compare two versions of test-mergesort because it always runs the helpers from the checked-out version. So I hand-merged the results of separate runs before and with this patch: macOS 12.5.1 on M1: 0071.12: DEFINE_LIST_SORT unsorted 0.22(0.20+0.01) 0.21(0.19+0.01) 0071.14: DEFINE_LIST_SORT sorted 0.10(0.08+0.01) 0.10(0.08+0.01) 0071.16: DEFINE_LIST_SORT reversed 0.10(0.08+0.01) 0.10(0.08+0.01) Git SDK 64-bit on Windows 11 21H2 on Ryzen 7 5800H: 0071.12: DEFINE_LIST_SORT unsorted 0.54(0.00+0.06) 0.44(0.01+0.06) 0071.14: DEFINE_LIST_SORT sorted 0.21(0.03+0.03) 0.19(0.04+0.01) 0071.16: DEFINE_LIST_SORT reversed 0.21(0.01+0.04) 0.19(0.04+0.04) Debian bullseye on WSL2 on the same system: 0071.12: DEFINE_LIST_SORT unsorted 0.29(0.27+0.01) 0.22(0.19+0.02) 0071.14: DEFINE_LIST_SORT sorted 0.07(0.06+0.01) 0.06(0.04+0.02) 0071.16: DEFINE_LIST_SORT reversed 0.07(0.04+0.03) 0.06(0.04+0.02) Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

René Scharfe committed Aug 28, 2022 at 12:34 UTC c333c2ce651d5b363ec67d33559ebd9a717ced68
1 file changed +3 -1
t/helper/test-mergesort.c
+3 -1
@@ -25,6 +25,7 @@ static int sort_stdin(void)
25 struct line *lines;
26 struct line **tail = &lines;
27 struct strbuf sb = STRBUF_INIT;
28 + struct mem_pool lines_pool;
29 char *p;
30
31 strbuf_read(&sb, 0, 0);
@@ -36,10 +37,11 @@ static int sort_stdin(void)
37 if (sb.len && sb.buf[sb.len - 1] == '\n')
38 strbuf_setlen(&sb, sb.len - 1);
39
40 + mem_pool_init(&lines_pool, 0);
41 p = sb.buf;
42 for (;;) {
43 char *eol = strchr(p, '\n');
42 - struct line *line = xmalloc(sizeof(*line));
44 + struct line *line = mem_pool_alloc(&lines_pool, sizeof(*line));
45 line->text = p;
46 *tail = line;
47 tail = &line->next;